What happens when 50 million people plug in an Apple controller that requires little more investment then buying Apple stuff and plugging it in? You get a bubble market of casual shovelware games that destroy the credibility of the entire concept as a serious contender in the industry. You design a LCD (least common denominator) peripheral with LCD UI and LCD functionality so you can have a huge, market that couldn't care less about your product and can't wait to find an exciting risky alternative. Sounds great for quarterly profits though.